Windows only: Free application ToneThis makes it simple to create MP3 ringtones, wallpaper, and videos for your cellphone. Apart from its simple MP3 ringtone creator, ToneThis sports a lot of great features—like simple tools for sending media to supported phones in a few clicks. Unfortunately those features don't always work perfectly—as CNET can attest to—but as a simple ringtone and wallpaper creator, it does the job admirably. If you decide to give it a try, be sure to read the installer carefully—this thing tries its best to install all kinds of toolbars and other crap that you probably don't want. ToneThis is a free download, Windows only.